/**
  * Store Keywords in seprate dataobject
  *
  * @param array $authorsRawData, int $extensionId
  */
 public static function save_keywords($rawKeywordData, $extensionId)
 {
     $totalKeywords = count($rawKeywordData);
     for ($i = 0; $i < $totalKeywords; $i++) {
         if ($keyword = ExtensionKeywords::get()->filter("KeywordName", $rawKeywordData[$i])->first()) {
             $keyword->Extension()->add($extensionId);
         } else {
             $keyword = new ExtensionKeywords();
             $keyword->KeywordName = $rawKeywordData[$i];
             $keyword->write();
             $keyword->Extension()->add($extensionId);
         }
     }
 }